As reported in the Journal of Clinical Oncology by Higgins et al, the phase III NRG Oncology/Alliance LU005 trial showed no overall survival benefit with the addition of atezolizumab to concurrent chemoradiation (CRT) in patients with limited-stage small cell lung cancer (LS-SCLC).
Study Details
In the open-label, multicenter study, 544 patients with LS-SCLC (stage Tx-IV, N0-3, M0) received one cycle of chemotherapy (platinum/etoposide) prior to registration and were randomly assigned between May 2019 and December 2023 to receive CRT alone (n = 270) or CRT plus concurrent and adjuvant atezolizumab (n = 274). CRT consisted of cisplatin or carboplatin with etoposide plus radiotherapy at 66 Gy once daily or 45 Gy twice daily. Atezolizumab was given at 1,200 mg every 3 weeks until disease progression or intolerable side effects or for a maximum of 17 cycles. The primary endpoint of the trial was overall survival.
Key Findings
Median follow-up was 23.8 months for the total population and 32.4 months among surviving patients.
Median overall survival was 31.1 months (95% confidence interval [CI] = 28.5–44.7 months) in the CRT plus atezolizumab group vs 36.1 months (95% CI = 28.1–42.5 months) in the CRT-alone group (hazard ratio [HR] = 1.03, 95% CI = 0.80–1.32).
Median progression-free survival was 12.1 months (95% CI = 10.9–15.2 months) in the CRT plus atezolizumab group vs 11.4 months (95% CI = 10.3–13.2 months) in the CRT-alone group (HR = 0.98, 95% CI = 0.79–1.22). Median distant metastasis–free survival was 16.8 months (95% CI = 12.1–21.6 months) in the CRT plus atezolizumab group vs 13.0 months (95% CI = 11.3–18.2 months) in the CRT-alone group (HR = 0.96, 95% CI = 0.76–1.21).
Grade 3 to 4 adverse events occurred in 95.8% of the CRT plus atezolizumab group vs 94.2% of the CRT-alone group; grade 5 events occurred in 9.1% vs 1.6%. Immune-mediated adverse events of any grade occurred in 52.7% vs 18.3% and were of grade 3 to 4 in 17.8% vs 6.6%. Among adverse events of interest, grade ≥ 3 events included esophagitis in 10.6% vs 7.0% and pneumonitis in 6.1% vs 3.1%.
The investigators concluded: “Concurrent and adjuvant atezolizumab with chemoradiation did not improve survival in patients with LS-SCLC.”
Kristin A. Higgins, MD, of City of Hope Cancer Center, Atlanta, is the corresponding author for the Journal of Clinical Oncology article.
DISCLOSURE: The study was supported by the National Cancer Institute and Genentech. For full disclosures of the study authors, visit ascopubs.org.
